June 13, 2002

Hortiscope

Ronald C. Smith, Horticulturist
NDSU Extension Service

Q: We have two clump white birch, one of which is 15 years old and is a beautiful tree.

Very early this spring, the first part of April, it had buds on it, but now since the frost the middle to end of May it appears dead -- no green leaves, branches brittle, etc. A younger tree next to it is in the same shape. The really puzzling thing is a third clump birch -- the youngest of all -- is doing beautifully. My husband did put 10-10-10 fertilizer on all three trees the first part of May before that killing frost. Could that be the culprit? We are able to find green bark on the two bad looking birches but only on the main trunk. We also have a 4-year-old cottonwood that has leafed out but rather than green leaves they are yellow green similar to what you see in the fall when the tree is dying off. We have been TLC'ing the trees (frequent generous watering) but are wondering, should we be pulling them out and replanting with something else, or just be patient and maybe they will pull through? We're just sick about the birch as we have really nurtured them and they were just getting to be such handsome trees. (Wishek, N.D.)

A: Hold on for a few more weeks. If the tree has not re-leafed by the Fourth of July, then it is likely a goner, and the fertilizer your husband applied is not at fault. Borers sometimes get to these beautiful trees and kill them off when we are appreciating them the most. The cottonwood doesn't sound much better. I don't know what to tell you the problem is as it could be too many to consider. Most likely something is going on with the root system.

Q: Is there any grass other than either crested wheat or fairway crested wheatgrass that will tolerate saline soil conditions? Our Bottineau High School athletic fields sit on saline soils. They are having problems maintaining a decent turf. Do you know of any turfgrass species that can be interseeded to help thicken up turfgrass? (Bottineau, N.D.)

A: The most salt tolerant grasses that I know of that can be used in turf are saltgrass (Distichlis stricta), a warm-season grass, and alkaligrass (Puccinella distans 'Fults') a cool-season grass. Since your part of the country is considered a "cool" region, I suggest going for the latter. It isn't a pretty grass like the Kentucky blues, but it is very tolerant of soil salts.

Q: We moved to this area a year ago and we have three apple trees of an unknown variety. The former owner claimed that he never sprayed or treated them for insects at all and had wonderful crops of apples. We have just planted two Honeycrisp apple trees in the same area so we have a "mini-orchard" and would like to harvest non-wormy apples. My husband is not crazy about spraying the trees because of possible harm to his lungs and the environment. What is the best solution for us? (Eveleth, Minn.)

A: Apples without spraying is very much a possibility. You can get pheromone traps to attract the apple maggot, "false apples" that are covered with a sticky substance that will attract and hold other destructive insects as well. Then, it is simply following basic good sanitation -- picking up all apple litter in the fall (leaves and fallen apples), spraying with a dormant oil in early spring before leafing out takes place and properly pruning the trees to allow for good air circulation, sunlight penetration and of course easier picking. All will help to control insect and disease problems.

Q: I have access to hundreds of pasture grown 3- to 6-foot cedar trees. I would like to use a tree transplanter to dig many up and replant them in our yard. When is the best time to do this? I would like to do it now if its not to late. Also, how much water should I initially give them upon first planting? (Kimball, S.D.)

A: By cedar trees I assume you mean junipers, as I am sure that true "cedars" (Cedrus spp.) do not grow in either of our states. Success depends on a lot of things: How far the trees are going to be transported, how skilled the tree spade operator is in positioning the trees, the age/size of the trees, soil compatibility, and your access to a dependable water supply. The best time to move them is in early spring -- March or April -- or in the fall -- late September. They should receive a total soaking at first planting. This is accomplished by filling the hole the spade creates for the tree with water and allowing it to enter the surrounding soil. Once the tree is in place, lay a hose at the base of the tree and allow it to soak into the rootball. Repeat this soaking weekly through the growing season or as long as the soil is not frozen and the rainfall is inadequate to wet the soil completely. Whenever you do move the trees -- now, in the spring or in the fall -- it would be a good idea to spray the trees with an anti-desiccant like Wilt-Pruf to cut down on moisture loss that takes place when the trees are moved and the roots severed.

Q: I noticed my 10- year-old linden tree in the front yard is showing signs of trouble. The leaves are very small and some limbs do not have leaves at all. It appears some buds popped but got zapped by our cold weather this spring and never matured. I am encouraged to see some green on my tree although the linden across the street is fully leaved and looks great. Anything you can recommend to coax it along? I did lay the hose by the base to limit the stress of our dry conditions. (Carrington, N.D.)

A: Fickle Mother Nature, how she can frustrate us at times! If your linden has been where it is for 10 years or more, I don't think you have anything to worry about. There is bound to be some damage and the difference between the two trees could be the exposure they have as no two sites are exactly alike, and unless cloned, neither are the trees. Give it 30 days and I'll bet that the tree will green up nicely for you. Keep the water to it -- not soggy, but don't allow it to go too long without water if we don't get soaking rains on a regular basis. You might also want to give it a shot of fertilizer this month.

Q: My mother has a red rose bush planted next to her house. It has been there for many years. Until recently it always bloomed beautifully, but now it does not bloom at all. It hasn't bloomed for two years now. It has great plant growth but never puts on any flowers or buds. Other than digging it up and replacing it with another rose bush, is there anything we can do to make it bloom again? I can not tell you what kind of rose this one is, as it has been there for many years and no one can remember what kind it is, other than red. She always trims the bushes in the spring. As soon as regrowth starts, last years growth is trimmed off. She has several other rose bushes as well in the same area, and they all bloom great, and are all about the same age. (Reliance, S.D.)

A: What has happened is the scion (aka "budwood") has died off and the root stock is suckering new growth, which for the most part is flowerless. It has vigorous growth, but no flowers. The only thing you can do is replace it.

Q: What is the difference between roses advertised as miniature roses and those that say fairy roses, which are apparently similar in size. Jackson Perkins says "Fairy Roses" will winter in North Dakota with protection of some sort. I'm not sure about the miniature roses. Any thoughts? (E-mail reference)

A: I am not familiar with the Fairy Roses. If J&P claims they will winter in North Dakota with some protection, I'd make sure they got plenty! If they are not too expensive, give them a try if they appeal to you.

Q: My sister-in-law has a philodendron that is beautiful and full, but the other day she noticed that there are tiny silver bugs crawling all over the dirt. She has not seen them anywhere else in her house. What are these and are they harmful to the plant? What can she do to get rid of them? (E-mail reference)

A: They are probably the larval stage of fungus gnats or they could be earwigs. If they appear to be confined to the soil mass and show no interest in the aerial part of the plant, you can water the plant with a malathion solution. But first, get the plant out of doors or the odor will make everyone sick! A less-toxic approach would be to take everything outside and repot it in fresh soil after washing the roots completely with clear water.

Q: Could you tell me if it is OK to cut the suckers from my crab apple now, in June? (E-mail reference)

A: No problem, go for it.

Q: My piggy back plant is turning light green to yellow and the leaves are curling under. What can I do to prevent this? (E-mail reference)

A: I suspect that you have kept the mother plant beyond the point of being attractive and it is beginning to decline. I suggest propagating with a leaf that has a plantlet attached to create a new plant for you to admire. While these are "fun to grow" plants, they begin to look a little worse for wear if they have been around for awhile and been transplanted a couple of times, which I suspect yours has been.

Q: Some friends of ours have taken up the practice of removing the main leaders on all of their 2- to 4-year-old blue spruces with the assumption that they are creating a fuller, bushier tree. I can find no information anywhere that supports this idea. What do you think about topping trees? (Sioux Falls, S.D.)

A: Your friends are right. It will create a bush, not a tree. The leader is something that provides the vertical growth to the tree, and when it is removed or cut back without any other action taken, the tree will become shrub-form. Christmas tree growers follow a regular pruning practice on spruce, fir and pine that creates bushier trees than Mother Nature intended. Typically, the spruce make a nice cone shape anyway. The mistake they are making in doing that to the spruce is sooner or later they are going to stop, and what will the tree look like then? I wish I had photos of trees that had been "topped" for a decade or so, then let go. They turn out to look freakish.

Do you have a gardening or houseplant question? Write to Hortiscope, Box 5051, NDSU Extension Service, Fargo, ND 58105 or e-mail to Ron Smith at ronsmith@ndsuext.nodak.edu. Note to e-mail correspondents: please identify your location (city and state) for most accurate recommendations.

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Source: Ron Smith, (701) 231-8161, ronsmith@ndsuext.nodak.edu
Editor: Gary Moran, (701) 231-7865, gmoran@ndsuext.nodak.edu